Long-Term Assessment Of Predatory Fish Removal On A Pond-Breeding Amphibian Community In Central Illinois

Abstract

Habitat loss and fragmentation are important contributors to population declines in many species, so maintaining suitable habitat has become a priority for wildlife management. Removal of introduced fish can help restore suitable habitats for amphibian populations, although long-term assessments of such removals are lacking at the community level. In 2001, drift fences and pitfall traps were constructed around the majority of four ponds to monitor an amphibian community in a nature preserve in central Illinois. Rotenone™ was applied to ponds containing introduced fish in 2001, and again, in 2003. I collected data from 2005-2007 to determine the long-term impacts of fish removal on this amphibian community. There was no difference in species abundance across pond type and time period. Although no difference in species diversity was detected in either pond, before or after fish removal, species diversity tended to increase following fish removal in both pond types. The sizes of young-of-the-year Ambystoma texanum, Lithobates sphenocephalus, and L. sylvaticus young-of-the-year were smaller following fish removal. Small-mouthed Salamander (A. texanum) recruitment increased following fish removal, with treatment ponds responding better than control ponds. My results indicate that the removal of predatory fish has increased species diversity throughout WWNP, and also demonstrate the effectiveness of using Rotenone™ to remove predatory fish for improving habitat for pond-breeding amphibians without causing negative impacts on the latter group of species.

Date of Award	2009
Original language	American English
Awarding Institution	Eastern Illinois University
Supervisor	Stephen Mullin (Supervisor)